Silicon Nanoparticles (SiNPs) Enhance Elongation and Rooting of In Vitro Shoots of Vanilla (Vanilla planifolia Andrews) During Micropropagation in RITA® Bioreactors

Vanilla (<i>Vanilla planifolia</i> Andrews) cultivation is globally relevant due to the extraction of vanillin from its cured fruits. However, the high demand for propagules for commercial plantations requires new propagation methodologies, including in vitro propagation. Currently, the use of biostimulants in plant micropropagation protocols is being explored to increase the number of plants obtained and their vigor. Nanomaterials such as silicon dioxide nanoparticles (SiNPs) have shown a positive effect on plant growth and development. The objective of this study was to evaluate the effect of SiNPs on the micropropagation of <i>V. planifolia</i> in RITA^® bioreactors. In vitro plants were transferred to Murashige and Skoog (MS) medium supplemented with different concentrations of SiNPs < 50 nm (0, 50, 100, and 150 mg L^-1) in RITA^® bioreactors. The obtained plants were then acclimatized in a greenhouse. The results indicated that 150 mg L^-1 of SiNPs produced the highest average shoot number, with 5.12 shoots per explant (5.48 cm in length), 9.50 leaves, and 5.00 roots per explant. The formation of an optimal root system in plants with SiNPs allowed for 98% survival. Results will enable more efficient in vitro propagation protocols through the obtainment of plants with greater length and a developed root system that facilitates ex vitro adaptation.